Best practice for variable and method naming in Java

All Java components require names. Names used for classes, variables and methods are called identifiers. In Java, there are several points to remember about identifiers. They are as follows -

• All identifiers should begin with a letter (A to Z or a to z), currency character ($) or an underscore (_). 
• After the first character, identifiers can have any combination of characters.
• A keyword cannot be used as an identifier. 
• Most importantly, identifiers are case sensitive. 
• Examples of legal identifiers: age, $salary, _value, __1_value. 
• Examples of illegal identifiers: 123abc, -salary.